Particles and Fields Nuclear Physics

Marietta Blau

Pioneering work in the photographic method of studying particle tracks. She
created emulsions with characteristics and development conditions that
allowed for observation and measurement of
proton tracks.

"Blau was indeed the first physicist to show that proton tracks could be
separated from alpha-particle tracks in emulsion. Of course, lots of
physicists had studied alpha tracks from the alpha-decay of very heavy nuclei
in the emulsion, from very early times, in the 1890s, and even earlier. She
went further, by identifying proton tracks resulting from a) the elastic
scattering of alphas by protons in the hydrogen in the emulsion, and b) the
reactions of alphas with the nuclei of the emulsion. She also exposed emulsion
to neutron beams and measured the proton energies for protons resulting from
elastic scattering of the neutrons by the hydrogen in the emulsion. In
particular she used this method to detemine the spectrum of neutrons resulting from
specific nuclear reaction processes." -- Professor R. H. Dalitz, Oxford University.

First to use nuclear emulsions to detect neutrons - by observing recoil protons.

Worked with Ilford (UK) to obtain thick emulsions, and
discovered development techniques to observe and measure track
of higher energy protons and used these to study and detect
protons and other heavy particles in cosmic rays.

Showed there were relatively large numbers of protons and neutrons in
cosmic radiation.

Observed nuclear disintegrations caused by cosmic rays in nuclear emulsions,
with H. Wambacher. These were known before WWII as Blau-Wambacher stars.